This invention relates generally to machines for stacking panels or sheets (the terms "panels" and "sheets" being used interchangeably herein) of plastic, plywood, plasterboard, counter tops, or the like in an even, well balanced pile on a floor surface, truck bed, pallet or other place of storage.
When the manufacture of a building panel, such as a sheet of plywood, is completed the panel is normally discharged from the output of a primary machine or a horizontal conveyor. As it is discharged from the conveyor the panel, normally 8' by 4', is grasped at each end by a worker and placed upon a pile on a pallet for storage and later movement to a lumber yard or building site.
Obviously, for proper balance and subsequent handling of the pallet the panels must be stacked evenly in the manner of a deck of cards. Inasmuch as these panels are relatively heavy and each must be deposited upon the stack at a slightly higher level than the preceding panel, the stacking heretofore has not readily lent itself to automation and to the applicant's knowledge has been done by hand as hereinbefore described. Where automatic stacking conveyors have been used the panels are dumped off of the discharge end of the conveyor requiring a backstop to aid in evening the stack.
The applicant is the owner of a copending application Ser. No. 890,258, filed Apr. 21, 1978, now abandoned, entitled Machine for Stacking Lumber, which is designed for stacking rows of side-by-side lumber boards in layers upon a pallet or the like.